Pollution is said to be the biggest killer in developing countries. Contaminated air, water and soil claim millions of lives every year. And with rapid urbanization and economic growth come fears that these numbers will only rise in years to come. In Uganda, the effects of pollution on people are becoming more visible.

The World Health Organization says more than 8 million people die around the world each year as a result of living in a polluted environment. In Kampala, Dr. Kiggundu Tamale said the effects of air pollution are becoming more and more noticeable.

“Air pollution has become one of the biggest challenges faced in Uganda, especially in urban centers… In Uganda, the main cause of air pollution is transport, especially rapid motorization that is being experienced in urban areas. But then there are other causes, like mining for example. Like open waste burning,” said Dr. Tamale.

Doctors say it’s often difficult to tie someone's health problems specifically to air pollution. In recent years, though, doctors in Uganda have seen an increase in the number of patients with lung problems.

Dr. William Worodria said air pollution has multiple effects.

“And particularly the lungs, the heart and other body systems. In the lungs you may have chronic lung disease, like bronchial asthma, chronic obstructed lung diseases. Even lung cancer has been reported associated with air pollution,” said Dr. Worodria.

Worldwide, the WHO says pollution kills more people than malaria, HIV/AIDS and tuberculosis combined. Yet, pollution often remains under the radar of policy makers.

Studies by Ugandan scientists suggest about 14 percent of children between the ages of 8 and 14 living in Kampala have bronchial asthma. Dr. Worodria said researchers found similar results in one of Uganda's rural districts.

“They looked at other forms of pollution, which include indoor pollution from smoke and other things and again about 14 percent of inhabitants of that rural district had some form of chronic obstructed lung diseases,” he said.

Scientists and health officials say one reason air pollution is not a higher priority is that it's less visible than other problems..

"For example, if you have a poor road infrastructure, this is visible enough. If you don’t have electricity, this is visible. So our politicians tend to focus more on problems that are visible by people. But air pollution is less visible and therefor our decision makers or policy makers do not see it as a priority,” said Dr. Tamale.

Recently, however, Ugandan health officials and the government, have started a campaign to raise awareness about lung disease caused by air pollution.

One suggested approach includes trying to get people out of their cars and walking -- before Uganda becomes congested not only by cars but by their exhaust fumes.